Chronic cholecystitis is prolonged, or long-standing, inflammation of the gallbladder. It is a very common condition that is more frequently seen in young and middle-aged women. Chronic cholecystitis is typically caused by gallstones that get stuck in the cystic duct, which is a tube that connects the gallbladder to the small bowel. Most people with chronic cholecystitis experience abdominal pain after eating.
The gallbladder is a small, pear-shaped organ located below the liver, in the right, upper portion of the abdomen. Doctors often describe this area as the right, upper quadrant. The gallbladder is a hollow organ that stores bile, which is a specialized fluid made in the liver. Bile aids in digestion and is typically released from the gallbladder after a meal. The gallbladder releases bile by contracting.
The wall of the gallbladder is made up of a thick bundle of muscle that allows the gallbladder to contract. This contraction pushes bile out of the gallbladder and down a tube called the cystic duct and then into a part of the small bowel called the duodenum.
The inside of the gallbladder is lined with a thin layer of tissue called mucosa. The surface of the mucosa is covered with epithelial cells that form a barrier called the epithelium. Below the epithelium is a thin layer of connective tissue called lamina propria.
Gallstones are hard, stone-shaped collections of biological material that build up in the gallbladder. Pathologists use the term, ‘cholelithiasis’, to describe gallstones. Most gallstones are made of cholesterol that comes from the liver. Gallstones can also be made up of bilirubin, which forms when red blood cells break down, or the mineral calcium. Gallstones can cause chronic cholecystitis by filling the gallbladder and preventing it from contracting normally, or by blocking one of the tubes that connect the gallbladder to the small bowel.
This picture shows an opened gallbladder with gallstones inside
The diagnosis of chronic cholecystitis is made after the gallbladder is removed in a procedure called a cholecystectomy. This surgical procedure is usually performed after imaging, such as an ultrasound or CT scan, of the gallbladder shows features that are consistent with chronic cholecystitis.
When examined under the microscope, the gallbladder of an individual with chronic cholecystitis shows evidence of prolonged or chronic inflammation. Specifically, a variety of inflammatory cells, including neutrophils, lymphocytes, plasma cells, and histiocytes, are usually seen in the mucosa on the inside of the gallbladder. Cholesterol is often seen inside the cells that line the gallbladder. Pathologists describe this change as cholesterolosis.
With chronic cholecystitis, the muscular wall of the gallbladder is typically much thicker than normal. Pathologists describe this change as hypertrophy. Hypertrophy occurs because the gallbladder is forced to work harder to get bile past gallstones. In some cases, the epithelium on the inner surface of the gallbladder is pushed deep into the muscular wall. Pathologists describe these areas as Rokitansky-Aschoff sinuses.
Finally, adenomyomas are sometimes seen in a gallbladder removed in an individual who has chronic cholecystitis. Adenomyomas (also called adenomatous hyperplasia) are groups of non-cancerous cells, connected together and forming round structures called glands, and surrounded by bundles of muscle cells. They are found within the wall of the gallbladder.